In the case of subseq, the replacement value must be a sequence whose elements might be contained by the sequence argument to subseq, but does not have to be a sequence of the same type as the sequence of which the subsequence is specified. If the length of the replacement value does not equal the length of the subsequence to be replaced, then the shorter length determines the number of elements to be stored, as for replace.

* A function call form whose first element is the name of a selector function constructed by defstruct. The function name must refer to the global function definition, rather than a locally defined function.

* A function call form whose first element is the name of any one of the functions in the next figure, provided that the supplied argument to that function is in turn a place form; in this case the new place has stored back into it the result of applying the supplied ``update'' function.

Figure 5-8. Functions that setf can be used with---2 During the setf expansion of these forms, it is necessary to call get-setf-expansion in order to figure out how the inner, nested generalized variable must be treated.

5. Do the write into place-form with the given bits of the integer fetched in step 4 replaced with the value from step 3.

If the evaluation of value-form in step 3 alters what is found in place-form, such as setting different bits of integer, then the change of the bits denoted by byte-spec is to that altered integer, because step 4 is done after the value-form evaluation. Nevertheless, the evaluations required for binding the temporary variables are done in steps 1 and 2, and thus the expected left-to-right evaluation order is seen. For example:

the place referred to by place-form must always be both read and written; note that the update is to the generalized variable specified by place-form, not necessarily to the particular list that is the property list in question.

5. Do the write into place-form with a possibly-new property list obtained by combining the values from steps 2, 3, and 4. (Note that the phrase ``possibly-new property list'' can mean that the former property list is somehow destructively re-used, or it can mean partial or full copying of it. Since either copying or destructive re-use can occur, the treatment of the resultant value for the possibly-new property list must proceed as if it were a different copy needing to be stored back into the generalized variable.)

If the evaluation of value-form in step 3 alters what is found in place-form, such as setting a different named property in the list, then the change of the property denoted by ind-form is to that altered list, because step 4 is done after the value-form evaluation. Nevertheless, the evaluations required for binding the temporary variables are done in steps 1 and 2, and thus the expected left-to-right evaluation order is seen.